Ultraviolet radiation is primarily emitted by what source?

Ultraviolet (UV) radiation is primarily emitted by sunlight. The sun is a natural source of UV radiation, which is part of the electromagnetic spectrum and is present in sunlight in various wavelengths. UV radiation from the sun is responsible for both beneficial effects, such as stimulating vitamin D production in the skin, and harmful effects, including skin damage and increased risk of skin cancer.

While other sources listed, such as power plants, industrial processes, and household appliances, may emit different types of radiation or pollutants, they are not significant sources of ultraviolet radiation compared to the sun. For instance, power plants primarily emit pollutants like carbon dioxide or sulfur dioxide, while industrial processes may emit various chemicals but are not known for UV radiation. Household appliances typically operate within safety limits and do not emit significant levels of UV radiation. Therefore, sunlight is the most prominent and crucial source of UV radiation that impacts health and the environment.